Device for the prevention of back-fire to the carburetors for internalcombustion engines and for other purposes



March 3, 1931. q BlCHLER 1,795,245

DEVICE FOR THE PREVENTION OF BACK FIRE TO THE CARBURETORS FOR INTERNALCOMBUSTION ENGINES AND FOR OTHER PURPOSES Filed March 16. 1929 4Sheets-Sheet 1 Fig.1

lg: ui'l 1 Q o m o gll all 2 HWzf/VTOR Charles fiBzchZer HTTORNEKS Mach3,. 1931.

C. H. BICHLER DEVICE FOR THE PREVENTION OF BACK FIRE TO THE CARBURETORSFOR INTERNAL COMBUSTION ENGINES AND FOR OTHER PURPOSES 7H Filed March 4Sheets-Sheet 2 INVENTOR CharZea/iBzc/Mr 'HTTO RNEYS DEVICE FOKTHE'PREVENTION OF BACK FIRE 1'0 THE CARBURETORS March 3, 1931. Q HL1,795,245

FOR INTERNAL COMBUSTION ENGINES AND FOR OTHER PURPOSES Filed llax ch 16.1929. 4 Sheets-She. 3

. g n 73 i #1 I 3 I F 9 w, mm M44 1 1925 Fig.1

I 15 04- I 16 H lfVVENTOR Charles liBwhZer HTTORNEY March 3, 1931. c. H.BICHLER 1,795,245

DEVICE FOR THE PREVENTION OF BACK FIRE TO THE CARBURETORS FOR INTERNALCOMBUSTION ENGINES AND FOR OTHER PURPOSES Filed March 16. 1929 4Sheets-Sheet 4 23 v 7.9 V INyENTORS i Charles HEM/2M" HTTORNEYS PatentedMar. 3, 1931 UNITED STATES PATENT. OFFICE CHARLES HENRI BIcHLER, orPARIS, FRANCE DEVICE FOR THE PREVENTION OF BACK-FIRE TO THE CARBURETORSFOR INTERNAL- COMBUSTION EETGINES AND FOR OTHER PURPOSES Applicationfiled. March 16, 1929, Serial. no. 342,713, d in France ifuly 23, 1928.

The present invention relatesto a device for the prevention of back-fireto the carburetor, for internal combustion engines and for otherpurposes. I

It has been already proposed, for the prevention of-back-fire' tothecarburetor in internal combustion engines, to dispose in the suctionconduit suitable plates which are properly spaced apart and thus form aset which allows thefree circulation of the fuel mixture to theengine'but prevents all return of the flames to the carburetor. The'setor plates is disposed in the admission con duit at a suitable pointbetween the carburetor and the engine;

The present invention has for its object a special arrangement of thesaid plates for the prevention "of backfire, in which the sets of plateshave a square, rectangular, polygonal, circular or other cross sectionand are disposed in conduits or portions of conduits of correspondingform situated between the carburetor and the engine, or even before thecarburetor, said plates being assembled by connecting members which holdthem properly spaced apart and are disposed ator near the edges of theplates, thus leaving the middle part of the plates entirely free. In

this manner, the gas will have a free circu- 39 lation, avoidingobstruction to the fuel gas in the admission conduit. Means I are alsoprovided for heating the fuel gas preferably in an adjustablemanner'disposed before the set of plates or extending through saidplates whereby the engine will be properly supplied iuall cases. In theaccompanying drawing which represents various embodiments ofjthe invention;

Figs. 1 and 2 are respectively an elevational view with parts brokenaway, and an end view with partial cross-section, of a square sectionconduit containing a set of plates of square section.

5 Figs. 3 and 4 are respectively an end view and an elevational View ofa set of plates adapted to be placed in a cylindrical conduit. v 7

Fig. 5 is aset of plates fitting upon the :1." outlet of the carburetorin the casein which spaceiswanting at the end of the carburetor tocontain a normal set of plates. I F igs. 6, 7 and'8 are respectively anelevational view, a left hand end View and a right hand end view,.of amodification comprising partially movable flanges.

V Fig. 9 is a partial section of a modified form of the device shown inFigures 1 and 2, the section in Figure 9 being made according to twodifferent half planes whereof one passes through the heating tube andthe other at the outside of the said tube.

F ig.- 10 is a perspective view of one of the plates shown in Figure 9.Fig. 11 is a detailofthe device holding the set of plates according toFigure 9' Fig. 12 is a general view showing the circulation of theheating fluid used for the admission conduit.

In the form of construction shown in Fig ures 1 and 2, there is mountedupon the usual fuel feed pipe of the internal combustion engine aconduit 1 of square cross-section, provided with the connecting flanges20f the known form by which the said conduit can be mounted upon thepipes leading respectively to the carburetor and the cylinder head ofthe engine. r a

Inthe'interior of the said conduit 1 are disposed the plates 3 insuitable number, these being held at the proper distance apart byspacing bolts 4 which as shown chiefly in Fig. 2 are disposed near theedges of the said plates, leaving the middle part of the conduit free. i

By this arrangement, the gas stream will circulate freely in the middlepart of the set of plates without obstruction from the said spacingbolts, and, since the central part of the gas stream will normallytravel at the greatest speed, the obstruction offered to the circulationof the gas in the conduit containing the spaced plates will have aminimum effect in opposing the circulation of the gas from thecarburetor to the engine. On the other hand, since the said plates forma homogeneous set, they will provide an adequate cooling surface forpreventing all access of theflame to the carburetor, the coolingsurfacebeing increased by the use of the square cross-section for thesaid conduit, whereby the width of the said plates can be muchincreased.

To further provide for the proper space in the central part of suchconduits in the case of conduits of circular cross-section containingcylindrical sets of plates, the said plates (Fig. 2-3) are assembled byspacing bolts 5 which are situated at the proper distance on either sideof the lon itudinal axis of the system, and whose ends are securedto theplates (3 3) situated at a suitable dis tance from the longitudinalaxis. The said plates (3 are in turn secured to the end plates of theset by the spacing bolts 7 which are provided in suitable member and areproperly distributed along the height of the said plates. 7

In Fig. 9, the partial half-section on the right shows a tube 17connecting the opposit-e plates 18 of the heating jacket, thus rais ingthe temperature of the gas mixture leaving the carburetor, in order toprevent all formation of frost upon the plates 9. As shown in Fig. 10,each of the plates 9 has at the middle of its lower part a notch 19fitting upon the tube 17 i of suitable cross-section in order to assurethe proper radiation in the plates 9, of the heat supplied by the tube17. instead of maintaining the set of plates in position by screws shownat 20 in Figure 1, there is preferably disposed 011 either side of theset of plates a tongue 21. (Fig. 11) having a nip 22 engaging inperforations in the end plates of the set, as shown on the left of Fig.9. At the bottom of each tongue 21 is a flange 23, which in theassembled position will be engaged in a recess of the cmrrespoi'ulingflange 2.

To further the heating of the device for the prevention of frost thereis disposed on the channel 25 for the circulation of the water for theheating of the usual conduits, a main transverse pipe 26 (Fig. 12)connecting the upper ends of the jacket serving to heat the conduits 2728 supplying the heating water (or other flui d) to the plates 18 ofFigure 9. The water which has circulated in said plates will then issuethrough the pipes 29-3(l (Fig. 12 in order to heat the outlet of thecarburetors 3132.

To reduce the heating of the conduits 27-28 at will, the devicecomprises a by-pass 33 starting from the conduit 25 and coinmunicatingby a transverse tube 34 with the pipes 29 which supply heating water tothe carburetors 3132.

The heating tube 17 provided in the apparatus may have any desiredheight according to the temperature to whichthe plates 9 are to beheated. The said tube 17 may have the same height as the plates 9, andif desired, this tube can be used as a separating partition. dividinginto two sections each of the conduits 27-28 containing the said plates9.

In this case, the said plates may be disposer in guides provided in thelateral face of the tube 17 and also in the walls 17 of the saidconduit, thus dispensing with any other retaining device.

The heating is preferably rendered adjustable by providing at a suitablepoint of the heating circuit 25 6833&, one or more cocks or the likewhich permit to determine with all necessary precision the amount of thewater (or other) circulation for heating purposes in the usual conduitsand also in the conduit containing the plates or blades 27-28, saidparts being provided with suitable controlling means placed within thedrivers reach. The said heating jacket, instead of being disposed asshown in Figures 1 and 9, may extend as far as the most re strictedsection of the flange 2, and herein the transverse heating tube 17 maybe eliminated.

In the construction shown in Figure 5 which represents a very shortconduit in which there is not sufficient room to dispose the set ofplates, the said plates 9 are herein disposed mixing chamber 8 includedin a discharge conduit of the carburetor, whose casing 10 is held inposition by the screws 11. The plates replace the Venturi shown indotted lines.

To reduce the size of the apparatus, one end of the set of plates is cutout at 12 in order to fit upon the sprayer 13 of the carburetor.

It is also feasible to leave the usual venturi in the casing 10, and itmay occupy the lower part of said casing, which herein will contain noplates, or the usual disposition may be employed in which the saidplates will have a suitable shape to conform to the configuration of theVenturi wall.

Figs. 6 to 8 show an arrangement adapted to reduce the obstruction tothe gas flow which is caused by the said plates, and herein one part ofthe set of plates is fixed and the other part movable.

The fixed part (Figs. 6 and 7) comprises plates 15 which are spacedapart by double the distance which is recognized as necessary toextinguish the flames, this distance being increased by the thickness ofa plate.

The set of stationary plates 15 carries an axle 13 (Figs. 6 and 8) towhich is pivoted a secondset of plates 14, held together by cross-bolts16 and bevelled at 17 (Fig. 8) to enable their release, when pivoting,from the said stationary plates 15, the whole device being mounted in aconduit not shown.

The movable plates 14 are spaced apart by the same distance as thestationary plates 15 and are disposed in the respective spaces betweenthe latter, as shown chiefly in Fig. 8.

During the normal functioning of the engine, whose suction conduitcontains the sets 14 and 15, the gas from the carburetor circulating inthe direction of the arrow (Fig. 6) will drive the movable set 14 intothe position shown in the dot-and-dash lines, and thus there will be noobstacle to the gasfiow through the device.

In the case of. back fire to the carburetor,

that is, in the contrary direction to the arrow,

the said movable set 1 1, which is no longer driven back by the suctiongas, will fall by its own weight into the position shown in the fulllines, this action being furthered by the force of the ignited gascirculating in the contrary direction to the arrow, and in consequencethe sets 1l15 will have the relative position shown in Fig. 8, in whichthey now form a single set whose plates have the proper spacing toobstruct the ignited gas, whereby the carburetor will be well protectedfrom the flames.

The sets formed by the plates 14 and the plates 15 may be placed in anyposition whether vertical, horizontal or inclined, although the verticalposition is preferable. The movable set 14 might also be made slidablewith reference to the fixed set 15.

The fixed set and the movable set of plates may be given any suitableshape, depending upon the form of the conduits in which they aredisposed.

In the various constructions herein represented, the sets of plates maybe disposed not only between the carburetor and the engine, but also infront of the carburetor andupon the air intake conduit. It is preferableto combine these two arrangements in such manner as to prevent allaccess of flames not only to the carburetor but also to any point of theengine admission piping, whereby all danger from this cause will beobviated.

The said invention is adapted for the pre- 'vention of back-fire to thecarburetor in all types of internal combustion engines whether for aircraft or for other uses, and more gen- 11 erally, in all cases in whicha fuel mixture circulates in a conduit.

What I claim is: r 1. A device for preventing back fire to thecarburetor, for internal combustion engines and for other uses whichcomprises a special disposition of the sets of anti-back-fire plates, inwhich the sets of plates whose cross-section is square, rectangular,polygonal, circular or the like, which are disposed in condults orportions of conduits of corresponding form,

. mounted between the carburetor and the engine, or even in front of thecarburetor, are

held together by connecting means, which hold them apart at a suitablerelative dis- I tance, and which are disposed at the edges missionconduit, an arrangement being provided to permit anydesired heating,preferably adjustable, of the fuel mixture, either in front of the setof plates or across the set of plates, in such manner as to assure inall cases the proper feed to the engine.

2. A form of construction of the device according to claim 1, in whichthe plates forming the sets of plates are mounted in the dischargeconduit of the carburetor in the place usually occupied by the venturiof said carburetor in such manner as to assure an effective protectionof the carburetor against the return of the flames, even when thesuction conduit of the engine is too short to contain a set of the usualanti-back-fire plates, and the venturi of the carburetor may also haveplaced upon it the said set of plates, in such manner as to reduce thesize.

3. A modification comprising the combination of two sets of platesdisposed along the.

to prevent in a practically complete manner all obstruction tothesuction gas of the engine, while effectively preventing all travel ofthe ignited gas.

In. testimony whereof I have hereunto set my hand at Paris this fifthday of March,

CHARLES HENRI BICHLER.

